function openInterests = getOpenInterest( openInterestMap, year_letter, put_letter, call_letter, strikes )

openInterests = zeros( length(strikes), 2 );
for i = 1:length( strikes )
    K = num2str( strikes(i) );
    openInterests( i,1 ) = openInterestMap( strcat('OBX', year_letter, call_letter,K) );
    openInterests( i,2 ) = openInterestMap( strcat('OBX', year_letter, put_letter,K) );
end

end